Gas burner assemblies



July 9, 1963 v. WEBER 3,09

GAS BURNER ASSEMBLIES Filed March 12, 1959 United States Patent 3,986,813 GAS BURNER ASSEMBLIES Victor Weber, Greenshurg, Pa., assignor to Robertshaw- Fulton Controls Company, Richmond, Va., a corporation of Delaware Filed Mar. 12, 1959, Ser. No. 798,899 1 Claim. (Cl. 158-116) This invention relates to gas burner assemblies and more particularly to burner assemblies of the type primarily intended for use as top burners on domestic gas range appliances.

Such burner assemblies generally comprise a burner head mounted on a mixing tube which has an air shutter for controlling the flow of primary air. These burners are classified as atmospheric burners and utilize the Bunsen principle wherein the pressure of the gas supplied is utilized to increase its velocity through an orifice to entrain a quantity of primary air into the mixing tube.

One of the main objects of this invention is to provide an improved burner assembly having one or more of the novel features hereinafter shown or described.

Other objects and advantages of this invention will be apparent from the following description taken in connection with the accompanying drawings wherein:

FIG. 1 is an enlarged elevational view, partly in section, of the burner assembly of this invention.

FIG. 2 is a plan view of the burner shown in FIG. 1.

As illustrated in FIGS. 1 and 2, front burner assembly 20 comprises an end plate 42 and an air shutter 44. Plate 42 is formed with a lug 46 which is inserted through a hole in tube 36 and is reversely bent to secure plate 42 to tube 36. Plate 42 is formed with a central opening (not shown) into which orifice 30 is inserted for admitting gas into tube 36. A tab 48 extends rearwardly from plate 42 and is formed with a threaded aperture which receives an adjusting screw 50. The air shutter 44 has a semi-circular configuration and is adapted to cover the upper half of the inlet end of tube 36 to provide means for adjusting the flow of primary air. The shutter 44 is formed with an elongated slot 52 through which screw 50 passes and which when loosened allows shutter 44 to slide along tube 36 relative to plate 42 to the position corresponding to the desired rate of primary air intake.

Tube 36 is formed from two sheet metal members 54 and 56, preferably made from commercially pure aluminum, which are first joined at their edges, and then separated at the median portion as by inflation to form a venturi 58, a diffuser 59, and a support base for burner head 34. Venturi 58 has a circular cross section and is formed with the usual throat and diffuser portions. The venturi diffuser terminates at the inlet to diffuser 59 which has a substantially rectangular cross section.

To form a supporting base for burner head 34, tube 36 is provided with an annular head having suitably formed apertures into which a burner cap 60 and an adaptor 62 are inserted, as best shown in FIG. 1, and respectively interconnected to the lower and upper surfaces of the burner head support base. Member 56 is strengthened by a depression 64 into which the base of cap 60 is inserted.

Cap 60 is formed with a substantially outwardly-extending curved flange 66, which is connected to a flue portion 68 through which secondary air is adapted to flow. The lower end of flue 68 is formed with a shoulder which rests upon the top surface of member 56 and a neck 70, of reduced diameter, which passes through member 56. In this embodiment, cap 60* is detachably secured to the lower surface of the tube 36 by a generally U-shaped spring 72 which fits into a pair of grooves 74, 74 formed in neck 70.

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The spring 72 is formed with a pair of legs which are bent inwardly towards each other. The legs are also bowed slightly. When inserted into grooves 74, 74 the bowed portion biases cap 60 into engagement with member 56 and allows for slight differences in dimensions due to manufacturing tolerances. To remove cap 60, it is merely necessary to bend legs 76 and 78 outwardly until they are separated from grooves 74, 74 at which point cap 60 may be lifted. Since this expedient would be somewhat cumbersome in most gas ranges, spring 72 may be dispensed with together with grooves 74, 74 thus, cap 60 would merely rest on member 56, being held in a concentric arrangement by the neck 70. In this case, it is only necessary to lift cap 60 to remove it.

Adaptor 62 is formed with a tubular body having an outwardly extending flange formed at the upper end which cooperates with flange 66 to form a continuous peripheral burner port 80. The lower end of adaptor 62 is formed with a shoulder which abuts the top surface of member 54, and a collar 82, having a reduced diameter, which passes through member 54. Collar 82 is preferably flared outwardly at an angle of approximately 45 to sandwich a portion of member '54 between the outwardly flared portion and the shoulder for the purpose of rigidly attaching adaptor 62 to tube 36 whereby the adapter 62 is secured to the upper surface of the burner head support base.

Cap 60 cooperates with tube 36 to form an annular distribution chamber 84. An outlet passage 86 extends from chamber 84 to port between adaptor 62 and cap 60. Flue 68 is formed with a necked-down portion 88 which cooperates with adaptor 62 to form an annular nozzle and throat 89 by means of which the gas velocity is increased as it passes through outlet passage 84. It will be obvious that this nozzle could also be made by deforming adaptor 62 in a similar manner.

It has been found that the distance b, shown in FIG. 1, which corresponds to the radial thickness of throat 89, should be between one-third to one-eight of the distance a, which corresponds to the distance between the flanges, for maintaining a minimum flame length. At high flow rates, the flame is directed outwardly from port 80, whereas at minimum flow rates, the flame burns within port 80 adjacent to throat 89.

It will be obvious to those skilled in the art that many changes and modifications may be made in the details of construction and arrangement of parts without departing from the scope of the invention as defined in the appended claim.

I claim: 7

Ina burner assembly provided with a burner head support base having upper and lower surfaces, a burner head comprising: a first tubular member connected at one end to the upper surface of said support base and being formed at the other end with a first outwardly extending flange, a second tubular member connected at one end to the lower surface of said support base and being formed at the other end with a second outwardly extending flange, said tubular members having vertically extending body portions arranged concentric to one another to form an annular flow passage between said body portions and :a peripheral port between said flanges, and a necked-down portion on one of said tubular members reducing in diameter said flow passage to increase the velocity of fluid flowing through said flow passage to said burner port without turbulence thereof, said neckeddown portion progressively and smoothly reducing the cross sectional area of said flow passage toward said burner port throughout a major portion of said flow passage, the width of said reduced cross sectional area of said annular flow passage being between one-third to one-eighth of the distance between the flanges of said tubular members.

References Cited in the file of this patent UNITED STATES PATENTS Matthews et a1 Feb. 8, 1938 Jaros May 25, 1943 Mills Mar. 19, 1946 Thiele July 2, 1946 Reeves Ian. 23, 1951 Abrams Mar. 4, 1952 Weseman May 6, 1952 Hays et a1 Dec. 29, 1959 FOREIGN PATENTS France July 12, 1938 

